Christina Aguilera was protected by fiance Jordan Bratman, after a frightening encounter with a drunken fan.

The Beautiful singer was discussing wedding plans with Bratman, at Hollywood's Mood bar, when the fan interrupted and asked for an autograph. However, Bratman was forced to step in when things turned nasty.

"Christina wrote the autograph, but the guy kept hassling her," an onlooker told the Daily Star. "The bloke was yelling something like, 'Here now, come here or I'll...' and then the sentence just trailed away.

"Christina, who is such a tiny thing, struggled to break free from him. She then stood on the sofa screaming 'Get out! Get out!'

"Her boyfriend went nuts and just dashed in and threw the guy up against the wall. Christina made a call and then all the security rushed in. He was really heroic."